IRC:
* Fix "Registration timeout" on SASL auth with InspIRCd servers
(and possibly others not based on charybdis/ratbox/ircd-seven)
* Fix issues with plugins that modify outgoing messages
(such as the custom PART/QUIT feature of the IRC More plugin)
* Fix IRC buffer handling. (#12562 PR #272 Shivaram Lingamneni)
* Properly handle AUTHENTICATE as a normal command with server prefix.
(PR #316 dx)
* Fix a crash caused by a use after free of the MOTD.
* Fix an out of bounds read in irc_nick_skip_mode.
* Fix a write of a single byte before the start of a buffer in
irc_parse_ctcp.